An Hashtable-backed dictionary that enumerates Keys and Values in insertion order.
/*
[The "BSD licence"]
Copyright (c) 2005-2007 Kunle Odutola
All rights reserved.
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derived from this software without specific prior WRITTEN permission.
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submitted for inclusion in this work to the copyright owner or licensor
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namespace Antlr.Runtime.Collections
{
using System;
using IDictionary = System.Collections.IDictionary;
using IDictionaryEnumerator = System.Collections.IDictionaryEnumerator;
using ICollection = System.Collections.ICollection;
using IEnumerator = System.Collections.IEnumerator;
using Hashtable = System.Collections.Hashtable;
using ArrayList = System.Collections.ArrayList;
using DictionaryEntry = System.Collections.DictionaryEntry;
using StringBuilder = System.Text.StringBuilder;
/// <summary>
/// An Hashtable-backed dictionary that enumerates Keys and Values in
/// insertion order.
/// </summary>
public sealed class HashList : IDictionary
{
#region Helper classes
private sealed class HashListEnumerator : IDictionaryEnumerator
{
internal enum EnumerationMode
{
Key,
Value,
Entry
}
private HashList _hashList;
private ArrayList _orderList;
private EnumerationMode _mode;
private int _index;
private int _version;
private object _key;
private object _value;
#region Constructors
internal HashListEnumerator()
{
_index = 0;
_key = null;
_value = null;
}
internal HashListEnumerator(HashList hashList, EnumerationMode mode)
{
_hashList = hashList;
_mode = mode;
_version = hashList._version;
_orderList = hashList._insertionOrderList;
_index = 0;
_key = null;
_value = null;
}
#endregion
#region IDictionaryEnumerator Members
public object Key
{
get
{
if (_key == null)
{
throw new InvalidOperationException("Enumeration has either not started or has already finished.");
}
return _key;
}
}
public object Value
{
get
{
if (_key == null)
{
throw new InvalidOperationException("Enumeration has either not started or has already finished.");
}
return _value;
}
}
public DictionaryEntry Entry
{
get
{
if (_key == null)
{
throw new InvalidOperationException("Enumeration has either not started or has already finished.");
}
return new DictionaryEntry(_key, _value);
}
}
#endregion
#region IEnumerator Members
public void Reset()
{
if (_version != _hashList._version)
{
throw new InvalidOperationException("Collection was modified; enumeration operation may not execute.");
}
_index = 0;
_key = null;
_value = null;
}
public object Current
{
get
{
if (_key == null)
{
throw new InvalidOperationException("Enumeration has either not started or has already finished.");
}
if (_mode == EnumerationMode.Key)
return _key;
else if (_mode == EnumerationMode.Value)
return _value;
return new DictionaryEntry(_key, _value);
}
}
public bool MoveNext()
{
if (_version != _hashList._version)
{
throw new InvalidOperationException("Collection was modified; enumeration operation may not execute.");
}
if (_index < _orderList.Count)
{
_key = _orderList[_index];
_value = _hashList[_key];
_index++;
return true;
}
_key = null;
return false;
}
#endregion
}
private sealed class KeyCollection : ICollection
{
private HashList _hashList;
#region Constructors
internal KeyCollection()
{
}
internal KeyCollection(HashList hashList)
{
_hashList = hashList;
}
#endregion
public override string ToString()
{
StringBuilder result = new StringBuilder();
result.Append("[");
ArrayList keys = _hashList._insertionOrderList;
for (int i = 0; i < keys.Count; i++)
{
if (i > 0)
{
result.Append(", ");
}
result.Append(keys[i]);
}
result.Append("]");
return result.ToString();
}
public override bool Equals(object o)
{
if (o is KeyCollection)
{
KeyCollection other = (KeyCollection) o;
if ((Count == 0) && (other.Count == 0))
return true;
else if (Count == other.Count)
{
for (int i = 0; i < Count; i++)
{
if ((_hashList._insertionOrderList[i] == other._hashList._insertionOrderList[i]) ||
(_hashList._insertionOrderList[i].Equals(other._hashList._insertionOrderList[i])))
return true;
}
}
}
return false;
}
public override int GetHashCode()
{
return _hashList._insertionOrderList.GetHashCode();
}
#region ICollection Members
public bool IsSynchronized
{
get { return _hashList.IsSynchronized; }
}
public int Count
{
get { return _hashList.Count; }
}
public void CopyTo(Array array, int index)
{
_hashList.CopyKeysTo(array, index);
}
public object SyncRoot
{
get { return _hashList.SyncRoot; }
}
#endregion
#region IEnumerable Members
public IEnumerator GetEnumerator()
{
return new HashListEnumerator(_hashList, HashListEnumerator.EnumerationMode.Key);
}
#endregion
}
private sealed class ValueCollection : ICollection
{
private HashList _hashList;
#region Constructors
internal ValueCollection()
{
}
internal ValueCollection(HashList hashList)
{
_hashList = hashList;
}
#endregion
public override string ToString()
{
StringBuilder result = new StringBuilder();
result.Append("[");
IEnumerator iter = new HashListEnumerator(_hashList, HashListEnumerator.EnumerationMode.Value);
if (iter.MoveNext())
{
result.Append((iter.Current == null) ? "null" : iter.Current);
while (iter.MoveNext())
{
result.Append(", ");
result.Append((iter.Current == null) ? "null" : iter.Current);
}
}
result.Append("]");
return result.ToString();
}
#region ICollection Members
public bool IsSynchronized
{
get { return _hashList.IsSynchronized; }
}
public int Count
{
get { return _hashList.Count; }
}
public void CopyTo(Array array, int index)
{
_hashList.CopyValuesTo(array, index);
}
public object SyncRoot
{
get { return _hashList.SyncRoot; }
}
#endregion
#region IEnumerable Members
public IEnumerator GetEnumerator()
{
return new HashListEnumerator(_hashList, HashListEnumerator.EnumerationMode.Value);
}
#endregion
}
#endregion
private Hashtable _dictionary = new Hashtable();
private ArrayList _insertionOrderList = new ArrayList();
private int _version;
#region Constructors
public HashList() : this(-1)
{
}
public HashList(int capacity)
{
if (capacity < 0)
{
_dictionary = new Hashtable();
_insertionOrderList = new ArrayList();
}
else
{
_dictionary = new Hashtable(capacity);
_insertionOrderList = new ArrayList(capacity);
}
_version = 0;
}
#endregion
#region IDictionary Members
public bool IsReadOnly { get { return _dictionary.IsReadOnly; } }
public IDictionaryEnumerator GetEnumerator()
{
return new HashListEnumerator(this, HashListEnumerator.EnumerationMode.Entry);
}
public object this[object key]
{
get { return _dictionary[key]; }
set
{
bool isNewEntry = !_dictionary.Contains(key);
_dictionary[key] = value;
if (isNewEntry)
_insertionOrderList.Add(key);
_version++;
}
}
public void Remove(object key)
{
_dictionary.Remove(key);
_insertionOrderList.Remove(key);
_version++;
}
public bool Contains(object key)
{
return _dictionary.Contains(key);
}
public void Clear()
{
_dictionary.Clear();
_insertionOrderList.Clear();
_version++;
}
public ICollection Values
{
get { return new ValueCollection(this); }
}
public void Add(object key, object value)
{
_dictionary.Add(key, value);
_insertionOrderList.Add(key);
_version++;
}
public ICollection Keys
{
get { return new KeyCollection(this); }
}
public bool IsFixedSize
{
get { return _dictionary.IsFixedSize; }
}
#endregion
#region ICollection Members
public bool IsSynchronized
{
get { return _dictionary.IsSynchronized; }
}
public int Count
{
get { return _dictionary.Count; }
}
public void CopyTo(Array array, int index)
{
int len = _insertionOrderList.Count;
for (int i = 0; i < len; i++)
{
DictionaryEntry e = new DictionaryEntry(_insertionOrderList[i], _dictionary[_insertionOrderList[i]]);
array.SetValue(e, index++);
}
}
public object SyncRoot
{
get { return _dictionary.SyncRoot; }
}
#endregion
#region IEnumerable Members
IEnumerator System.Collections.IEnumerable.GetEnumerator()
{
return new HashListEnumerator(this, HashListEnumerator.EnumerationMode.Entry);
}
#endregion
private void CopyKeysTo(Array array, int index)
{
int len = _insertionOrderList.Count;
for (int i = 0; i < len; i++)
{
array.SetValue(_insertionOrderList[i], index++);
}
}
private void CopyValuesTo(Array array, int index)
{
int len = _insertionOrderList.Count;
for (int i = 0; i < len; i++)
{
array.SetValue(_dictionary[_insertionOrderList[i]], index++);
}
}
}
}
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